A. Field of the Invention
The present invention relates to methods and apparatus for compacting low-density articles and more particularly to a method and apparatus for compacting low density articles, such as aluminum beverage containers, into "biscuits" of substantially uniform size and weight without weighing the articles prior to compaction.
B. Description of the Prior Art
In recent years, there has been substantial interest in recycling metals in order to conserve natural resources and to conserve energy and capital in connection with refining metals from ores. A metal of particular interest and for recycling is aluminum and aluminum beverage can collection centers have become commonplace. The cans are collected at the collection center for transportation back to the manufacturer.
Empty aluminum beverage cans are of very low density and in order to make their transportation more efficient, they need to be compacted into a more dense form. In the industry, aluminum beverage cans are compressed into compact blocks known as "biscuits" weighing between 18 and 22 pounds. Approximately 700 empty aluminum beverage cans are required to make a biscuit. It is of course, however, impractical in the interest of efficiency to count out 700 cans. Also, because the cans arrive at the collection center in various states of compaction--i.e., some of the cans are crushed or flattened--it is not possible to make a standard biscuit from a particular volume of cans; 20 pounds of flattened cans occupies substantially less volume than 20 pounds of unflattened cans.
There are machines in existence which weigh the cans prior to compaction. Such machines typically include a compaction chamber into which the cans are introduced and a ram which moves into and out of the compaction chamber to compress the cans. Such machines also include weighing mechanisms for monitoring the weight of cans fed to the compaction chambers. Such machines are well adapted for large scale applications, but they are complex and are not well adapted for small scale use.
Accordingly, it is an object of the present invention to provide an improved compaction apparatus and method that overcomes the shortcomings of the prior art.
It is a further object of the present invention to provide an apparatus and method for compacting articles into biscuits of substantially uniform size and weight without the need to weight the uncompacted articles.